Post by CoolP on Dec 14th, 2010 at 5:38pm
:) No problem, Mark, all those nasty little words from back in the days seem to come back at you when you catch that flying by the numbers.
Don't expect me to be an expert, I just investigate somehow and could be very wrong on some things too. Always willing to learn.
So I'm always thankful for manuals and stuff giving insights. Although my ordinary work should give me one too on some aspects, I seem to be the better listener/reader in the after work hours. ;D
I had a nice table once where they showed the accuracy of "common" (INS isn't common anymore) navigation instruments. Those GPS based units advanced it by a large margin, although there are many variants of them, not all able to be described as "GPS based".
Here's a good one too from Wikipedia.
(looks black, but click it and it lightens up)
The main factor on every GPS thingy is the usability in my eyes. Even the older FMC driven aircraft update their stuff on the fly (by all means) and the pilot just checks.
Flying INS based means constant attention, lots of error sources when entering data and awkward display codes to read.
So back to your update, the green "update" flag should come on when performing DME updates. If it stays off, something was entered the wrong way, the signal was lost or the procedure never started.
Another indicator, if you don't use the flag instrument, is the FROM-TO display (No.7).
Switch to the WAYPT position and look how that display performs considering 4) in that list.
Don't expect me to be an expert, I just investigate somehow and could be very wrong on some things too. Always willing to learn.
So I'm always thankful for manuals and stuff giving insights. Although my ordinary work should give me one too on some aspects, I seem to be the better listener/reader in the after work hours. ;D
I had a nice table once where they showed the accuracy of "common" (INS isn't common anymore) navigation instruments. Those GPS based units advanced it by a large margin, although there are many variants of them, not all able to be described as "GPS based".
Here's a good one too from Wikipedia.
(looks black, but click it and it lightens up)
The main factor on every GPS thingy is the usability in my eyes. Even the older FMC driven aircraft update their stuff on the fly (by all means) and the pilot just checks.
Flying INS based means constant attention, lots of error sources when entering data and awkward display codes to read.
So back to your update, the green "update" flag should come on when performing DME updates. If it stays off, something was entered the wrong way, the signal was lost or the procedure never started.
Another indicator, if you don't use the flag instrument, is the FROM-TO display (No.7).
Switch to the WAYPT position and look how that display performs considering 4) in that list.